Description of the Prior Art
Conditioning compositions heretofore provided in the art for the treatment of fabrics in one or more cycles of an automatic laundering process usually include, regarding softening and bleaching in particular, either a bleaching or softening agent.
Combination of these materials in a unitary composition is at best but vaguely suggested as regards specific types of ingredients, proportions and the like. Moreover, in such cases, it is indicated as being necessary to use the bleach material in dry form, and in substantial excess on a weight basis with respect to any softener compound which might be peripherally included within the relevant teaching. Peroxygen bleaches in such cases are usually limited to the normally solid, water-soluble type such as the alkali metal and ammonium perborates, percarbonates, mono-persulfates and monoperphosphates, species of the foregoing including for example sodium and potassium perborates and percarbonates. The aforementioned normally solid, inorganic peroxygen bleaches are usually employed in combination with various types of solid activators such as those disclosed in U.S. Pat. No. 3,130.165.
U.S. Patents relevant to the foregoing discussion include U.S. Pat. Nos. 3,945,936; 3,870,145; 3,994,694; 3,956,556; 3,634,947; 3,947,971 and 3,283,357.
The bleach component is usually added to the washing or drying cycle in solid form as described in U.S. Pat. No. 3,945,936 and British Pat. No. 1,456,592. It is recognized that wash cycle bleach compositions in liquid form are currently being marketed; however, such compositions do not include, nor is provision made for the inclusion of softener.
Softener compounds on the other hand, are conventionally added to the laundering process suitably dispersed in a liquid carrier, which may in turn be incorporated, e.g., by impregnation into a solid carrier support. Relevant in this regard are U.S. Pat. Nos. 3,442,692 and 3,632,396 describing the incorporation of liquid solutions or dispersions of softener e.g., quaternary ammonium compounds, into an absorbent sponge type substrate and substrates of open pore structure from nonwoven cloth paper, etc. of various shapes such as puffs, balls and the like. Other U.S. Patents relevant to softener materials and structures for their dispensing in a laundering process include U.S. Pat. Nos. 3,870,145; 3,944,694; 3,956,556; 3,634,947; 3,947,971; 3,442,692 and 3,632,396.
Conditioning compositions in liquid form offer several advantages such as, ready dissolution or dispersion in the washing medium or damp fabrics in the laundry dryer, homogeneity via solubilization of solid and/or liquid components in the conditioner solvent, facility of dispensing, e.g. by simple pouring enhanced accuracy of predetermined dosage amounts due to the increased volume of conditioner solution being handled by the user, etc. By way of contrast, the use of solid conditioning compositions entails significant disadvantages such as the rather elaborate and cumbersome structures required for their efficient dispensing in the machine as well as the difficulties inherent in the compounding of solid ingredients in the form of a coherent, homogeneous mass having adequate structural as well as chemical stability.
Moreover, conditioning compositions thus far provided but a single function, e.g. bleaching or softening, requiring therefore, the use of separate compositions during the washing-drying process according to a predetermined sequence of addition. The inconvenience to the user is readily apparent.
Thus, in copending application (filed simultaneously herewith) there are described liquid bleach-softener compositions capable of providing simultaneous bleaching, softening, detergency, antistat properties, etc., when added to one more of the wash, rinse and dryer cycles of an automatic machine laundering process. The result is considered surprising since it would normally be expected that problems associated with, for example, compatibility and stability of the involved ingredients and particularly in a liquid environment normally considered to be highly conducive to undesired fugitive side reactions, would militate against any possible effectiveness. Thus, prior art attempts to combine softener and bleach in a single composition have stressed the requirement for solid rather than liquid vehicles and even then under relatively stringent limitations as regards mutual proportions of active ingredients, assuring for example, the presence of bleach in at least substantial excess over softener. Thus, the recognized tendency of many softeners to form insoluble gels when present together with a peroxy bleaching agent in an aqueous medium is a significant factor in the compounding of such composition.
A wide variety of solid carried for conditioning compositions of the aforementioned type are discussed in the prior art ranging from non-woven cloth to open pore or open cell type flexible foam materials usually prepared from synthetic polymeric substances such as those based on polyurethanes. Although this type of substrate has been impregnated with various types of fabric conditioning compositions to provide convenient dispensing means for use in the appropriate cycle of the laundering process, the impregnating composition is invariably limited to the bleach or softener type. This apparently obtains in deference to the what would normally be expected unstable nature of the peroxide bleach in an aqueous environment in the presence of other oxidizable materials. The use of porous foam type carriers or substrates for such compositions would likewise be contraindicated since any unstable peroxide behavior might well be exascerbated by intimate confinement within a structure which could serve as a supply of sites or loci for degradative oxidation. This is particularly the case where extended storage periods under even ambient temperatures might be contemplated.
Consequently, in those instances where compositions combining peroxy bleach and softener are even remotely contemplated, it is required that such compositions be in dry form for introduction to the carrier substrate. The disadvantages here are numerous. As is commonly recognized, for optimum bleaching effects, it is necessary that the bleach composition be added to an aqueous environment. Addition to the wash cycle presents little problem; however, when added to the dryer substantially all of the bleach composition must be released during the initial phase of the drying cycle to insure the presence of sufficient moisture from the damp laundry to supply a reaction medium for the bleach. With solid bleach compositions, special precautions must be taken in fabricating the carrier substrate to guard against tardy release of the composition. Usually, the composition is sealed within a cavity provided in the substrate, the latter being, for example, an open pore cellular polymeric foam such as polyurethane. The tumble action of the dryer forces the composition to sift through the porous carrier for contact with the damp fabrics. In such structures, the particle size of the conditioning composition must be rigorously controlled vis-a-vis the average pore diameter of the substrate so that the dry composition is able to gravitate or sift through the structure for release to the damp fabrics. Moreover, as stated, this must occur during the initial portion of the dryer cycle. If conditioner release is too rapid, uneven deposition of the conditioner to the fabric usually occurs. On the other hand, should release be too slow, a portion of the composition may remain in the dry state, i.e. non-dissolved due to inadequate moisture, and be lost by venting from the dryer or alternatively, appear as an undesirable dust deposit on the fabrics.
Thus, a primary object of the invention is to provide an article for dispensing of liquid bleach softener composition wherein the foregoing and related disadvantages are eliminated or at least mitigated to a substantial extent.
A further object of the invention is to provide such an article capable of providing effective bleaching and softening when added to one or more of the wash, rinse and drying cycles of a fabric laundering process.
A still further object of the invention is to provide such an article capable of dispensing effective amounts of bleach softener composition during the optimum portion of the laundering cycle, release of composition being initiated by tumbling action.
Yet a still further object of the invention is to provide such an article wherein problems associated with loss of composition by dusting, and undesired spotting of fabrics by dust residues are eliminated.
Another object of the invention is to provide such an article having good compatibility with the bleach-softener ingredients and thus improved stability over prolonged periods of time at ambient and elevated temperatures.
Still another object of the invention is to provide such an article completely safe for use with dyed synthetic fabrics, such as Dacron, Dacron-cotton, permanent press as well as natural fibers.
Yet another object of the invention is to provide such an article of relatively simple construction, thus enabling more economical mathods of manufacture.
Another object of the invention is to provide a process employing such article in the conditioning of fabrics in a laundering process.
Other objects and advantages of the invention will become more apparent hereinafter as the description proceeds.